(1) Field of the Invention
The present invention relates to a power supply arrangement for a reactor for producing polysilicon, with a frequency converter, with at least one input for receiving an input current from a power grid, with which the input can be connected, and outputs for connecting one or several loads, via which the load or the loads can be supplied with an output current.
(2) Description of Related Art
The document EP 2 100 851 A2 discloses power supply arrangements which include frequency converters and which can be supplied with electrical energy from a single-phase power grid. Loads can be connected to the power supply arrangements with the frequency converters, for example silicon rods of a silicon reactor for producing polysilicon by vapor deposition according to the Siemens process.
FIG. 3 of the document EP 2 100 851 A2 shows that electrical energy is supplied to two loads connected in series separately from corresponding power supply arrangements with the frequency converters, wherein the power supply arrangements with a frequency converters are each configured single-phase. The phase between the currents provided by the power supply arrangements is 180°. The added voltages provided by the two power supply arrangements with frequency converters therefore cancel each other.
Power supply arrangements with frequency converters are described in the European patent applications having the application numbers 10 150 728 and 11 164 316 which were filed after the filing date of the present application, which have an output connected to a transformer having a primary winding and two secondary windings. The two secondary windings each have the same number of turns. However, they have the opposite winding sense. A voltage having the same magnitude but opposite polarity is then present at the outputs of the secondary windings. The secondary windings are connected to each other, with the connection forming a neutral conductor and the two ends of the secondary coils forming phase conductors of a two-phase AC current system which supplies a voltage to the connected loads.
The loads are each connected to at least conductor and to the neutral conductor of the two-phase AC current system.
The power supply arrangements with a frequency converter connected as described in the document EP 2 100 851 A2 and the power supply arrangements with frequency converters described in the applications 10 150 728 and 11 164 316 have the advantage that in addition to supplying the loads from the power supply arrangement having frequency converters, power can be simultaneously supplied from another power supply arrangement, without interference between the power supply arrangements. This approach is also described in the document EP 2 100 851 A2 and in the applications 10 150 728 and 11 164 316.
Disadvantageously, the circuit with two power supply arrangements with a frequency converter described in the document EP 2 100 851 A2 requires two frequency converters are for realizing the two-phase AC current system. Disadvantageously, the power supply arrangements with frequency converters described in the applications 10 150 728 and 11 164 316 require a special transformer with one primary winding and two secondary windings with opposite winding sense for realizing the two-phase AC current system.
Furthermore, the textbook “Leitungselektronische Schaltungen” by Dierk Schröder, ISBN 978-3-540-69300-0 discloses, for example, resonant circuit inverters and AC-AC converters, for example AC-AC converters with DC link energy storage or matrix converter, which are generally capable of providing multiphase AC current, in particular three-phase AC current. However, an application-specific description of the integration of the inverters or AC-AC converters in a power supply arrangement which is suitable or configured for polysilicon reactors is lacking in the textbook.
It is therefore the object of the invention to provide an improved power supply arrangement of the aforementioned type which is more efficient.